Precious metals are rare metallic chemical factors that fetch high and durable economic value. They're less reactive than most elements and are made distinct by their luster as well as their high melting points. The best known metals are gold and silver whose uses range widely from jewelry to coinage to art, and in the past years, have been renowned for their industrial significance as well. Platinum, which was basically a waste product, is now becoming one of the most widely traded precious metals and can include ruthenium, rhodium, palladium, osmium, and iridium. The nature of precious metals may be derived from the fact that they're very scarce and unique among other commodities which also account for their quality to be judged to become of great value, thus, a stride of wealth. It is also vital that you take into account that not every gold and silver stay precious forever. This relies on their availability and new methods for refining or perhaps creating such. Take aluminum, for example, once hard to outside of ore, it used to be the most difficult metal to get despite being one of the most common. Its status, which once put it above gold, dropped significantly when a simple aluminum extraction method is discovered in the late 1800's.
Fluctuations regarding the rarity of metals rely on demand. Silver, for one is within a supply deficit, using more silver than it is mined, and is then projected to cost even more than gold in the near future.
Aside from rarity, other common characteristics of metals for example uses, easy storage, similar origin and historical value are considered as criteria to be distinguished as gold and silver. It's also hard to deny the industrial purposes of gold and silver which make them even more appealing. Finding new ways to use them increases their market value in the trade and commodity market.